Contact Force
Identify the force that acts in the opposite direction to an action force.
Reaction Force
Identify a type of force that can attract or repel other magnetic materials
Magnetic Force
What is the SI unit of force?
Newton
One object has twice as much mass as another object. The first object also has twice as much
a. velocity. b. gravitational acceleration. c. inertia
c. inertia
If the mass of Earth increased, with no change in radius, your weight would _____.
a. stay the same b. decrease c. increase
c. increase
Opening the door is an example of which type of force?
(a) contact force b) spring force (c) non-contact force d) magnetic force
(a) contact force
Identify a force that attracts all objects with mass towards each other.
Gravity or gravitational force
Identify the name given to the combination of all forces acting on an object.
Net Force
After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals
a. zero, since no force is necessary to keep it moving. b. twice the force with which it was fired. c. one half the force with which it was fired. d. the same amount of force with which it was fired.
a. zero, since no force is necessary to keep it moving
Two objects move toward each other because of gravitational attraction. As the objects get closer and closer, the force between them _____.
a. remains constant b. decreases c. increases
c. increases
Identify the force resulting from surface interaction and adhesion during sliding.
Friction
A ball thrown in the air is an example of ____________ (type of force).
Gravitational force
Two identical low friction cars are filled with different amounts of wood. Car A has a much greater mass than car B. Both cars are given the same initial push. Which car slows down faster?
a. Car B slows down faster because it has less mass. b. Car B slows down faster because it has more mass. c. Car A slows down faster because it has more mass. d. Car A slows down faster because it has less mass.
a. Car B slows down faster because it has less mass.
A player hits a ball with a bat. The action force is the impact of the bat against the ball. What is the reaction to this force?
a) The weight of the ball b) Air resistance on the ball c) The force of the ball against the bat d) The grip of the player's hand against the bat
c. The force of the ball against the bat
Newton reasoned that the gravitational attraction between Earth and the moon must be _____.
a) independent of distance b) reduced by distance c)directly proportional to distance d. the same at all distances
b. reduced by distance
What kind of force an object that is being stretched experienced?
Tension
Which of the following is an example of a non-contact force?
(a) The force exerted by us to lift a bucket (b) push a stationary car (c) The force exerted by magnets d) Force due to friction
(c) The force exerted by magnets
A wagon is being pulled in a straight line. The forces exerted on the wagon are balanced. The wagon will __________.
a. speed up. b. slow down. c. move with a constant speed.
c. moves with a constant speed.
Suppose a cart is being moved by a force. If suddenly a load is dumped into the cart so that the cart's mass doubles, what happens to the cart's acceleration? a. It quarters. b. It halves. c. It stays the same. d. It doubles.
b. It halves
Suppose the gravitational force between two massive spheres is 100 N. If the distance between the spheres is doubled, what is the force between the masses?
a. 400 N b. 25 N c. 100 N d. 50 N
b. 25 N
A skydiver falling through the air is an example of _______________.
Air Resistance
The force exerted by a charged body on another charged or uncharged body is known as ______________.
Electrostatic charge.
You push a box on a smooth, smooth ice rink. Imagine the ice is frictionless. What happens while you push?
a. force is transferred to the box. b. energy is transferred to the box. c. force and energy are transferred to the box. d. neither force nor energy are transferred to the box.
b. energy is transferred to the box
You pull horizontally on a 50-kg crate with a force of 450 N and the friction force on the crate is 250 N. The acceleration of the crate is _______________.
a. 2 m/s2. b. 4 m/s2. c. 9 m/s2. d. 14 m/s2.
b. 4 m/s2
A planet has half the mass of the Earth and half the radius. Compared to its weight on Earth, an apple on this planet would weigh _____.
a. twice as much b. one-fourth as much c. half as much d. the same
a. twice as much